Self-study
Police commissioner: Support Last year our city experienced a 15 percent decrease in the rate of violent crime. ██ ███ █████████ ██ ████ ████ █ ███ █████████ ██████████ ███ ███ ████████ █████ ████████ ████ ███ ███████ █████████ █████ ████ ██ ███████ █████ ██ █████ █████ ██████ ███████ ████ ████ ████ █████ ███ ████ ██ ███ █████ ████ ████ ████ ████ ███ ██ ███ ███ █████████ ██████████ ████
Summarize Argument: Phenomenon-Hypothesis
The author concludes that last year’s 15 percent decrease in the rate of violent crime was caused by the new mandatory sentencing law. This is because the law was passed at the beginning of last year, and no other major policy changes were made last year.
Notable Assumptions
The author assumes that there was no alternate cause of the decreased crime rate. (Even though there were no other major policy changes last year, the crime rate could have decreased for some other reason that wasn’t a policy change, or from a policy change enacted before last year.)
24.
Which one of the following, ██ █████ ████ █████████ ███████ ███ ██████ ██████████████ █████████
a
Studies of many █████ ██████ ████ █████ █ ███████████ ███████ █████████ ████████ ██████████ ███ █████████ █████ ██████
We have no idea whether the author’s city had improved economic conditions. So, (A) doesn’t act as an alternate explanation for the decreased violent crime rate.
Failed alternate explanation
Failed alternate explanation
Weaken Qs: Answers that try to introduce an alternate explanation, but fall short, or try to explain a different phenomenon.
Strengthen Qs: Answers that try to eliminate an alternate explanation, but fall short, or try to eliminate an explanation for a different phenomenon.
b
Prior to the █████████ ██ ███ █████████ ██████████ ████ ██████ ██ ███ ████ ███ ███ ████ █████ ███████ ███████ █████████ █████ █████████ ███ ████ ███████
The mandatory sentencing law required prison time for all violent criminals. We have no idea whether the “unusually harsh penalties for some crimes” involved prison time for violent crimes.
c
Last year, the ██████ ███████ █████ ████ █████████ ██ ████ █ ████████
We know the violent crime rate decreased by 15 percent, which is higher than 5 percent. (C) helps support the theory that the decreased crime rate can’t be explained by a general decrease in crime.
Directionally wrong
Directionally wrong
Answers that, if they have any effect, do the opposite of what we want (weaken when we're trying to strengthen, or strengthen when we're trying to weaken).
d
At the beginning ██ ████ █████ ███ ██████ ████████████ ██████████ ██ ████████ ██████ ███ █████████ ██ ███████ █ ██████ ███ ██████████ ██████████ ██ ██████████
This strengthens the argument, because broadening the definition of “violent crime” would lead us to expect an increase in violent crime. This helps eliminate the explanation that the decreased violent crime rate was caused by a narrowing of the definition of violent crime.
Failed alternate explanation
Failed alternate explanation
Weaken Qs: Answers that try to introduce an alternate explanation, but fall short, or try to explain a different phenomenon.
Strengthen Qs: Answers that try to eliminate an alternate explanation, but fall short, or try to eliminate an explanation for a different phenomenon.
e
The city enacted █ ██████ █ █████ ███ █████████ ████ ███ ███ ██████ ████████ ██ █████ ██ ████ ██ ███ █ ██████████ ██████
This provides a potential alternate explanation for the decreased violent crime. (E) describes a policy change that was made prior to last year, but continued to have effects into last year. It’s reasonable to think increased numbers of police officers could reduce violent crime.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.